CVE-2026-3009

A security flaw in the IdentityBrokerService.performLogin endpoint of Keycloak allows authentication to proceed using an Identity Provider (IdP) even after it has been disabled by an administrator. An attacker who knows the IdP alias can reuse a previously generated login request to bypass the administrative restriction. This undermines access control enforcement and may allow unauthorized authentication through a disabled external provider.

What this means for your business

It affects Redhat Build Of Keycloak. It matters if your company, or a supplier that handles your data, runs it.
An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 26% of all known flaws.

What to do

1Check whether your company or your suppliers run Redhat Build Of Keycloak, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS: 8.1 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-863
Assigned by: secalert@redhat.com

Dates

Published: 2026-03-05
Last modified: 2026-09-14
Sources: NVD

Affected products

Redhat Build Of Keycloakall versions, 26.4, 26.4.10
Redhat Jboss Enterprise Application Platform8.0
Redhat Jboss Enterprise Application Platform Expansion Packall versions
Redhat Single Sign-On7.0

As listed in the NVD configuration data. Not a statement about your estate.